Large object parallel writing

ABSTRACT

A method includes partitioning data into first and second partitions and dispersed storage (DS) error encoding the first and second partition into first and second plurality of sets of encoded data slices (EDSs). The method further includes generating first SAT regarding storage of the first plurality of sets of EDSs and second SAT regarding storage of the second plurality of sets of EDSs. The method further includes DS error encoding the first and the second SAT to produce first and second sets of SAT slices, sending the first plurality of sets of EDSs and the first set of SAT slices to the first set of storage units, and sending the second plurality of sets of EDSs and the second set of SAT slices to the second set of storage units. The method further includes generating a third SAT regarding storage of the first and second sets of SAT slices.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority pursuant to 35 U.S.C. § 120 as acontinuation-in-part of U.S. Utility application Ser. No. 15/012,555,entitled “DETECTING STORAGE ERRORS IN A DISPERSED STORAGE NETWORK,”filed Feb. 1, 2016, which claims priority pursuant to 35 U.S.C. § 120 asa continuation of U.S. Utility application Ser. No. 13/890,438, entitled“DETECTING STORAGE ERRORS IN A DISPERSED STORAGE NETWORK,” filed May 9,2013, issued on Mar. 22, 2016 as U.S. Pat. No. 9,292,212, which claimspriority pursuant to 35 U.S.C. § 119(e) to U.S. Provisional ApplicationNo. 61/663,796, entitled “ACCESSING A DISTRIBUTED STORAGE AND TASKNETWORK,” filed Jun. 25, 2012, all of which are hereby incorporatedherein by reference in their entirety and made part of the present U.S.Utility Patent Application for all purposes.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not applicable.

INCORPORATION-BY-REFERENCE OF MATERIAL SUBMITTED ON A COMPACT DISC

Not applicable.

BACKGROUND OF THE INVENTION

Technical Field of the Invention

This invention relates generally to computer networks and moreparticularly to dispersing error encoded data.

Description of Related Art

Computing devices are known to communicate data, process data, and/orstore data. Such computing devices range from wireless smart phones,laptops, tablets, personal computers (PC), work stations, and video gamedevices, to data centers that support millions of web searches, stocktrades, or on-line purchases every day. In general, a computing deviceincludes a central processing unit (CPU), a memory system, userinput/output interfaces, peripheral device interfaces, and aninterconnecting bus structure.

As is further known, a computer may effectively extend its CPU by using“cloud computing” to perform one or more computing functions (e.g., aservice, an application, an algorithm, an arithmetic logic function,etc.) on behalf of the computer. Further, for large services,applications, and/or functions, cloud computing may be performed bymultiple cloud computing resources in a distributed manner to improvethe response time for completion of the service, application, and/orfunction. For example, Hadoop is an open source software framework thatsupports distributed applications enabling application execution bythousands of computers.

In addition to cloud computing, a computer may use “cloud storage” aspart of its memory system. As is known, cloud storage enables a user,via its computer, to store files, applications, etc. on an Internetstorage system. The Internet storage system may include a RAID(redundant array of independent disks) system and/or a dispersed storagesystem that uses an error correction scheme to encode data for storage.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)

FIG. 1 is a schematic block diagram of an embodiment of a dispersed ordistributed storage network (DSN) in accordance with the presentinvention;

FIG. 2 is a schematic block diagram of an embodiment of a computing corein accordance with the present invention;

FIG. 3 is a schematic block diagram of an example of dispersed storageerror encoding of data in accordance with the present invention;

FIG. 4 is a schematic block diagram of a generic example of an errorencoding function in accordance with the present invention;

FIG. 5 is a schematic block diagram of a specific example of an errorencoding function in accordance with the present invention;

FIG. 6 is a schematic block diagram of an example of a slice name of anencoded data slice (EDS) in accordance with the present invention;

FIG. 7 is a schematic block diagram of an example of dispersed storageerror decoding of data in accordance with the present invention;

FIG. 8 is a schematic block diagram of a generic example of an errordecoding function in accordance with the present invention;

FIG. 9 is a schematic block diagram of another embodiment of a dispersedstorage network (DSN) in accordance with the present invention;

FIG. 10 is a diagram illustrating an example of a directory inaccordance with the present invention;

FIG. 11 is a set of diagrams illustrating examples of segment allocationtables in accordance with the present invention; and

FIG. 12 is a flowchart illustrating an example of parallel storage ofdata in accordance with the present invention.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 is a schematic block diagram of an embodiment of a dispersed, ordistributed, storage network (DSN) 10 that includes a plurality ofcomputing devices 12-16, a managing unit 18, an integrity processingunit 20, and a DSN memory 22. The components of the DSN 10 are coupledto a network 24, which may include one or more wireless and/or wirelined communication systems; one or more non-public intranet systemsand/or public internet systems; and/or one or more local area networks(LAN) and/or wide area networks (WAN).

The DSN memory 22 includes a plurality of storage units 36 that may belocated at geographically different sites (e.g., one in Chicago, one inMilwaukee, etc.), at a common site, or a combination thereof. Forexample, if the DSN memory 22 includes eight storage units 36, eachstorage unit is located at a different site. As another example, if theDSN memory 22 includes eight storage units 36, all eight storage unitsare located at the same site. As yet another example, if the DSN memory22 includes eight storage units 36, a first pair of storage units are ata first common site, a second pair of storage units are at a secondcommon site, a third pair of storage units are at a third common site,and a fourth pair of storage units are at a fourth common site. Notethat a DSN memory 22 may include more or less than eight storage units36. Further note that each storage unit 36 includes a computing core (asshown in FIG. 2, or components thereof) and a plurality of memorydevices for storing dispersed error encoded data.

Each of the computing devices 12-16, the managing unit 18, and theintegrity processing unit 20 include a computing core 26, which includesnetwork interfaces 30-33.

Computing devices 12-16 may each be a portable computing device and/or afixed computing device. A portable computing device may be a socialnetworking device, a gaming device, a cell phone, a smart phone, adigital assistant, a digital music player, a digital video player, alaptop computer, a handheld computer, a tablet, a video game controller,and/or any other portable device that includes a computing core. A fixedcomputing device may be a computer (PC), a computer server, a cableset-top box, a satellite receiver, a television set, a printer, a faxmachine, home entertainment equipment, a video game console, and/or anytype of home or office computing equipment. Note that each of themanaging unit 18 and the integrity processing unit 20 may be separatecomputing devices, may be a common computing device, and/or may beintegrated into one or more of the computing devices 12-16 and/or intoone or more of the storage units 36.

Each interface 30, 32, and 33 includes software and hardware to supportone or more communication links via the network 24 indirectly and/ordirectly. For example, interface 30 supports a communication link (e.g.,wired, wireless, direct, via a LAN, via the network 24, etc.) betweencomputing devices 14 and 16. As another example, interface 32 supportscommunication links (e.g., a wired connection, a wireless connection, aLAN connection, and/or any other type of connection to/from the network24) between computing devices 12 & 16 and the DSN memory 22. As yetanother example, interface 33 supports a communication link for each ofthe managing unit 18 and the integrity processing unit 20 to the network24.

Computing devices 12 and 16 include a dispersed storage (DS) clientmodule 34, which enables the computing device to dispersed storage errorencode and decode data as subsequently described with reference to oneor more of FIGS. 3-8. In this example embodiment, computing device 16functions as a dispersed storage processing agent for computing device14. In this role, computing device 16 dispersed storage error encodesand decodes data on behalf of computing device 14. With the use ofdispersed storage error encoding and decoding, the DSN 10 is tolerant ofa significant number of storage unit failures (the number of failures isbased on parameters of the dispersed storage error encoding function)without loss of data and without the need for a redundant or backupcopies of the data. Further, the DSN 10 stores data for an indefiniteperiod of time without data loss and in a secure manner (e.g., thesystem is very resistant to unauthorized attempts at accessing thedata).

In operation, the managing unit 18 performs DS management services. Forexample, the managing unit 18 establishes distributed data storageparameters (e.g., vault creation, distributed storage parameters,security parameters, billing information, user profile information,etc.) for computing devices 12-14 individually or as part of a group ofuser devices. As a specific example, the managing unit 18 coordinatescreation of a vault (e.g., a virtual memory block associated with aportion of an overall namespace of the DSN) within the DSTN memory 22for a user device, a group of devices, or for public access andestablishes per vault dispersed storage (DS) error encoding parametersfor a vault. The managing unit 18 facilitates storage of DS errorencoding parameters for each vault by updating registry information ofthe DSN 10, where the registry information may be stored in the DSNmemory 22, a computing device 12-16, the managing unit 18, and/or theintegrity processing unit 20.

The DSN managing unit 18 creates and stores user profile information(e.g., an access control list (ACL)) in local memory and/or withinmemory of the DSN memory 22. The user profile information includesauthentication information, permissions, and/or the security parameters.The security parameters may include encryption/decryption scheme, one ormore encryption keys, key generation scheme, and/or dataencoding/decoding scheme.

The DSN managing unit 18 creates billing information for a particularuser, a user group, a vault access, public vault access, etc. Forinstance, the DSTN managing unit 18 tracks the number of times a useraccesses a non-public vault and/or public vaults, which can be used togenerate a per-access billing information. In another instance, the DSTNmanaging unit 18 tracks the amount of data stored and/or retrieved by auser device and/or a user group, which can be used to generate aper-data-amount billing information.

As another example, the managing unit 18 performs network operations,network administration, and/or network maintenance. Network operationsincludes authenticating user data allocation requests (e.g., read and/orwrite requests), managing creation of vaults, establishingauthentication credentials for user devices, adding/deleting components(e.g., user devices, storage units, and/or computing devices with a DSclient module 34) to/from the DSN 10, and/or establishing authenticationcredentials for the storage units 36. Network administration includesmonitoring devices and/or units for failures, maintaining vaultinformation, determining device and/or unit activation status,determining device and/or unit loading, and/or determining any othersystem level operation that affects the performance level of the DSN 10.Network maintenance includes facilitating replacing, upgrading,repairing, and/or expanding a device and/or unit of the DSN 10.

The integrity processing unit 20 performs rebuilding of ‘bad’ or missingencoded data slices. At a high level, the integrity processing unit 20performs rebuilding by periodically attempting to retrieve/list encodeddata slices, and/or slice names of the encoded data slices, from the DSNmemory 22. For retrieved encoded slices, they are checked for errors dueto data corruption, outdated version, etc. If a slice includes an error,it is flagged as a ‘bad’ slice. For encoded data slices that were notreceived and/or not listed, they are flagged as missing slices. Badand/or missing slices are subsequently rebuilt using other retrievedencoded data slices that are deemed to be good slices to produce rebuiltslices. The rebuilt slices are stored in the DSTN memory 22.

FIG. 2 is a schematic block diagram of an embodiment of a computing core26 that includes a processing module 50, a memory controller 52, mainmemory 54, a video graphics processing unit 55, an input/output (IO)controller 56, a peripheral component interconnect (PCI) interface 58,an IO interface module 60, at least one IO device interface module 62, aread only memory (ROM) basic input output system (BIOS) 64, and one ormore memory interface modules. The one or more memory interfacemodule(s) includes one or more of a universal serial bus (USB) interfacemodule 66, a host bus adapter (HBA) interface module 68, a networkinterface module 70, a flash interface module 72, a hard drive interfacemodule 74, and a DSN interface module 76.

The DSN interface module 76 functions to mimic a conventional operatingsystem (OS) file system interface (e.g., network file system (NFS),flash file system (FFS), disk file system (DFS), file transfer protocol(FTP), web-based distributed authoring and versioning (WebDAV), etc.)and/or a block memory interface (e.g., small computer system interface(SCSI), internet small computer system interface (iSCSI), etc.). The DSNinterface module 76 and/or the network interface module 70 may functionas one or more of the interface 30-33 of FIG. 1. Note that the IO deviceinterface module 62 and/or the memory interface modules 66-76 may becollectively or individually referred to as IO ports.

FIG. 3 is a schematic block diagram of an example of dispersed storageerror encoding of data. When a computing device 12 or 16 has data tostore it disperse storage error encodes the data in accordance with adispersed storage error encoding process based on dispersed storageerror encoding parameters. The dispersed storage error encodingparameters include an encoding function (e.g., information dispersalalgorithm, Reed-Solomon, Cauchy Reed-Solomon, systematic encoding,non-systematic encoding, on-line codes, etc.), a data segmentingprotocol (e.g., data segment size, fixed, variable, etc.), and per datasegment encoding values. The per data segment encoding values include atotal, or pillar width, number (T) of encoded data slices per encodingof a data segment i.e., in a set of encoded data slices); a decodethreshold number (D) of encoded data slices of a set of encoded dataslices that are needed to recover the data segment; a read thresholdnumber (R) of encoded data slices to indicate a number of encoded dataslices per set to be read from storage for decoding of the data segment;and/or a write threshold number (W) to indicate a number of encoded dataslices per set that must be accurately stored before the encoded datasegment is deemed to have been properly stored. The dispersed storageerror encoding parameters may further include slicing information (e.g.,the number of encoded data slices that will be created for each datasegment) and/or slice security information (e.g., per encoded data sliceencryption, compression, integrity checksum, etc.).

In the present example, Cauchy Reed-Solomon has been selected as theencoding function (a generic example is shown in FIG. 4 and a specificexample is shown in FIG. 5); the data segmenting protocol is to dividethe data object into fixed sized data segments; and the per data segmentencoding values include: a pillar width of 5, a decode threshold of 3, aread threshold of 4, and a write threshold of 4. In accordance with thedata segmenting protocol, the computing device 12 or 16 divides the data(e.g., a file (e.g., text, video, audio, etc.), a data object, or otherdata arrangement) into a plurality of fixed sized data segments (e.g., 1through Y of a fixed size in range of Kilo-bytes to Tera-bytes or more).The number of data segments created is dependent of the size of the dataand the data segmenting protocol.

The computing device 12 or 16 then disperse storage error encodes a datasegment using the selected encoding function (e.g., Cauchy Reed-Solomon)to produce a set of encoded data slices. FIG. 4 illustrates a genericCauchy Reed-Solomon encoding function, which includes an encoding matrix(EM), a data matrix (DM), and a coded matrix (CM). The size of theencoding matrix (EM) is dependent on the pillar width number (T) and thedecode threshold number (D) of selected per data segment encodingvalues. To produce the data matrix (DM), the data segment is dividedinto a plurality of data blocks and the data blocks are arranged into Dnumber of rows with Z data blocks per row. Note that Z is a function ofthe number of data blocks created from the data segment and the decodethreshold number (D). The coded matrix is produced by matrix multiplyingthe data matrix by the encoding matrix.

FIG. 5 illustrates a specific example of Cauchy Reed-Solomon encodingwith a pillar number (T) of five and decode threshold number of three.In this example, a first data segment is divided into twelve data blocks(D1-D12). The coded matrix includes five rows of coded data blocks,where the first row of X11-X14 corresponds to a first encoded data slice(EDS 1_1), the second row of X21-X24 corresponds to a second encodeddata slice (EDS 2_1), the third row of X31-X34 corresponds to a thirdencoded data slice (EDS 3_1), the fourth row of X41-X44 corresponds to afourth encoded data slice (EDS 4_1), and the fifth row of X51-X54corresponds to a fifth encoded data slice (EDS 5_1). Note that thesecond number of the EDS designation corresponds to the data segmentnumber.

Returning to the discussion of FIG. 3, the computing device also createsa slice name (SN) for each encoded data slice (EDS) in the set ofencoded data slices. A typical format for a slice name 60 is shown inFIG. 6. As shown, the slice name (SN) 60 includes a pillar number of theencoded data slice (e.g., one of 1-T), a data segment number (e.g., oneof 1-Y), a vault identifier (ID), a data object identifier (ID), and mayfurther include revision level information of the encoded data slices.The slice name functions as, at least part of, a DSN address for theencoded data slice for storage and retrieval from the DSN memory 22.

As a result of encoding, the computing device 12 or 16 produces aplurality of sets of encoded data slices, which are provided with theirrespective slice names to the storage units for storage. As shown, thefirst set of encoded data slices includes EDS 1_1 through EDS 5_1 andthe first set of slice names includes SN 1_1 through SN 5_1 and the lastset of encoded data slices includes EDS 1_Y through EDS 5_Y and the lastset of slice names includes SN 1_Y through SN 5_Y.

FIG. 7 is a schematic block diagram of an example of dispersed storageerror decoding of a data object that was dispersed storage error encodedand stored in the example of FIG. 4. In this example, the computingdevice 12 or 16 retrieves from the storage units at least the decodethreshold number of encoded data slices per data segment. As a specificexample, the computing device retrieves a read threshold number ofencoded data slices.

To recover a data segment from a decode threshold number of encoded dataslices, the computing device uses a decoding function as shown in FIG.8. As shown, the decoding function is essentially an inverse of theencoding function of FIG. 4. The coded matrix includes a decodethreshold number of rows (e.g., three in this example) and the decodingmatrix in an inversion of the encoding matrix that includes thecorresponding rows of the coded matrix. For example, if the coded matrixincludes rows 1, 2, and 4, the encoding matrix is reduced to rows 1, 2,and 4, and then inverted to produce the decoding matrix.

FIG. 9 is a schematic block diagram of another embodiment of adistributed or dispersed storage network (DSN) that includes a dispersedstorage (DS) client module 34 (e.g., of computing device 12 or 16) and aDSN memory 22. The DS client module 34 receives data 82 (e.g., a dataobject) for storage in the DSN memory 22. Based on a partitioning schemeor a data attribute (e.g., it may be desirable to partition the dataobject prior to dispersed error encoding is the data is within a sizerange), the DS client module 34 may partition the data 82 into at leasttwo data partitions. For each data partition of the at least two datapartitions, the DS client module 34 dispersed storage error encodes thedata partition to produce a plurality of sets of encoded data sliceswhere each set of encoded data slices corresponds to a data segment ofthe data partition. The encoding may be accomplished in a substantiallyparallel method such that while a first partition is being encoded asecond partition is simultaneously being encoded by another encodingresource potentially resulting in a system performance improvement. TheDS client module 34 outputs the plurality of sets of encoded data slicesto the DSN network 22 for storage therein.

For example, the DS client module 34 partitions the data 82 into a firstand second partition. The DS client module 34 then dispersed storageerror encodes the first partition into a first plurality of sets ofencoded data slices and the second partition into a second plurality ofsets of encoded data slices. The DS client module 34 then sends a firstplurality of sets of encoded data slices 84, corresponding to a firstdata partition, to a first set of storage units of the DSN memory 22 anda second plurality of sets of encoded data slices 86, corresponding to asecond data partition, to a second set of storage units of the DSNmemory 22.

The DS client module 34 updates a directory to associate the data 82with storage of the two or more pluralities of sets of encoded dataslices. For example, the DS client module 34 generates a segmentallocation table (SAT) vault source name for each data partition of theleast two data partitions to produce at least two SAT vault sourcenames. The DS client module 34 also generates a SAT vault source namefor the data 82. The DS client module 34 updates the directory toinclude the at least two SAT vault source names and for each SAT vaultsource name, a corresponding object descriptor of a data partitionassociated with the corresponding plurality of sets of encoded dataslices. The DS client module 34 also updates the directory to includethe SAT vault source name for the data 82. Such a directory is discussedin greater detail with reference to FIG. 10.

For each SAT vault source name associated with the at least two datapartitions, the DS client module 34 generates a SAT. The DS clientmodule 34 generates a SAT for the data 82 that includes a SATcorresponding to each of the at least two data partitions. Such a set ofSATs is discussed in greater detail with reference to FIG. 11.

FIG. 10 is a diagram illustrating an example of a directory 88 thatincludes an entry for data storage to a dispersed storage network (DSN)memory and an entry for each data partition of the data when two or moredata partitions are utilized to store the data in the DSN memory. Eachentry includes an object entry of an object field 90 and a segmentallocation table (SAT) vault source name entry of a SAT vault sourcename field 92. The object entry includes a descriptor of the data oreach data partition. The SAT vault source name entry includes a vaultsource name generated to store a corresponding SAT in the DSN memory.For example, data is partitioned into two data partitions andrepresented as data partition 1 and data partition 2. A SATcorresponding to data partition 1 is stored in a SAT vault source nameof 1A6B, a SAT corresponding to data partition 2 is stored in a SATvault source name of 48D2, and a SAT corresponding to the data is storedin a SAT vault source name of 34FA.

FIG. 11 is a set of diagrams illustrating examples of segment allocationtables (SATs) corresponding to storage of data in a distributed storagenetwork (DSN) memory when the data is partitioned into two or more datapartitions. Storage of a first partition of data is associated with aSAT stored at vault source name 1A6B and storage of a second partitionof data is associated with a SAT stored at vault source name 48D2.Another SAT is stored at vault source name 34FA that represents storageof the data as the two data partitions.

Each SAT includes a start segment vault source name entry of a startsegment vault source name field 94, a segment size entry of a segmentsize field 96, and a total length entry of a total length field 98. Thestart segment vault source name entry indicates a vault source nameassociated with storage of a set of encoded data slices of a firstsegment of one or more segments associated with the SAT. The segmentsize entry 96 indicates a number of bytes of each segment of the one ormore segments. The total length entry 98 indicates a number of bytes ofall of the one or more segments. For example, the first data partitionis stored as one or more segments starting with a first segment storedat a vault source name of AA01 where each segment is 100 bytes and atotal number of bytes of the first data partition is 500 bytes. Asanother example, the second data partition is stored as one of moresegments starting with a first segment stored at a vault source name ofBB05 where each segment is 100 bytes and a total number of bytes of thesecond data partition is 600 bytes.

The SAT associated with the data indicates the SAT information of thetwo or more data partitions as two or more regions of the SAT of thedata. The first region includes the start segment vault source name ofAA01 corresponding to the first data partition. The second regionincludes the start segment all source name of BB05 corresponding to thesecond data partition.

FIG. 12 is a flowchart illustrating an example of parallel storage ofdata in a dispersed storage network. The method begins at step 96 wherea processing module (e.g., of computing device of the DSN) partitionsdata for storage into two or more data partitions. For example, theprocessing module may partition a data object into a first partition anda second partition. The partitioning may be based on a partitioningscheme lookup, receiving the partitioning scheme, and an attribute ofthe data (e.g., size). For each partition, the method continues at step98 where the processing module dispersed error encodes each partitionutilizing a dispersed storage error coding function to produce aplurality of sets of encoded data slices. For example, the processingmodule may dispersed error encode the first partition into a firstplurality of sets of encoded data slices and the second partition into asecond plurality of sets of encoded data slices. A first set of thefirst plurality of sets of encoded data slices corresponds to a firstdata segment of a set of data segments of the first partition and afirst set of the second partition plurality of sets of encoded dataslices corresponds to a first data segment of a set of data segments ofthe second partition. The encoding may be accomplished in asubstantially parallel method such that while a first partition is beingencoded a second partition is simultaneously being encoded by anotherencoding resource potentially resulting in a system performanceimprovement.

For each partition, the method continues at step 100 where theprocessing module facilitates generating and storing a segmentallocation table (SAT) at a corresponding SAT vault source name. Forexample, the processing module generates a first segment allocationtable (SAT) regarding storage of the first plurality of sets of encodeddata slices in a first set of storage units of the DSN and a second SATregarding storage of the second plurality of sets of encoded data slicesin a second set of storage units of the DSN. The generating includesgenerating an entry for each field including a start segment vaultsource name field, a number of bytes per second field, and a number oftotal bytes for the partition field. The processing module may alsodispersed storage error encode the first SAT to produce a first set ofSAT slices and the second SAT to produce a second set of SAT slices.

For each partition, the method continues at step 102 where theprocessing module facilitates storing a corresponding plurality ofencoded data slices in the DSN memory in accordance with a correspondingSAT (e.g., storing starting with the start segment vault source name).For example, the processing module sends the first plurality of sets ofencoded data slices and the first set of SAT slices to the first set ofstorage units of the DSN memory and sends the second plurality of setsof encoded data slices and the second set of SAT slices to the secondset of storage units of the DSN memory. The facilitating includesgenerating write slice requests that includes the plurality of sets ofencoded data slices and sending the write slice requests to the DSNmemory.

For each partition, the method continues at step 104 where theprocessing module facilitates updating a directory to include acorresponding SAT vault source name. For example, a corresponding datapartition identifier is associated with the SAT vault source name of thedata partition. The method continues at step 106 where the processingmodule facilitates generating and storing a SAT for the data thatincludes SAT information for the two or more data partition's and acorresponding SAT vault source name for the data. For example, theprocessing module combines information from the two or more SATs in theSAT for the data. For instance, the processing module generates a thirdSAT regarding storage of the first and second sets of SAT slices in thefirst and second set of storage units. The processing module may thendispersed storage error encode the third SAT to produce a third set ofSAT slices and send the third set of SAT slices to the first set ofstorage units or the second set of storage units of the DSN memory.

The method continues at step 108 where the processing module updates thedirectory to include the SAT vault source name of the data. The updatingincludes establishing an association between the SAT vault source nameof the data and a data identifier of the data.

It is noted that terminologies as may be used herein such as bit stream,stream, signal sequence, etc. (or their equivalents) have been usedinterchangeably to describe digital information whose contentcorresponds to any of a number of desired types (e.g., data, video,speech, audio, etc. any of which may generally be referred to as‘data’).

As may be used herein, the terms “substantially” and “approximately”provides an industry-accepted tolerance for its corresponding termand/or relativity between items. Such an industry-accepted toleranceranges from less than one percent to fifty percent and corresponds to,but is not limited to, component values, integrated circuit processvariations, temperature variations, rise and fall times, and/or thermalnoise. Such relativity between items ranges from a difference of a fewpercent to magnitude differences. As may also be used herein, theterm(s) “configured to”, “operably coupled to”, “coupled to”, and/or“coupling” includes direct coupling between items and/or indirectcoupling between items via an intervening item (e.g., an item includes,but is not limited to, a component, an element, a circuit, and/or amodule) where, for an example of indirect coupling, the intervening itemdoes not modify the information of a signal but may adjust its currentlevel, voltage level, and/or power level. As may further be used herein,inferred coupling (i.e., where one element is coupled to another elementby inference) includes direct and indirect coupling between two items inthe same manner as “coupled to”. As may even further be used herein, theterm “configured to”, “operable to”, “coupled to”, or “operably coupledto” indicates that an item includes one or more of power connections,input(s), output(s), etc., to perform, when activated, one or more itscorresponding functions and may further include inferred coupling to oneor more other items. As may still further be used herein, the term“associated with”, includes direct and/or indirect coupling of separateitems and/or one item being embedded within another item.

As may be used herein, the term “compares favorably”, indicates that acomparison between two or more items, signals, etc., provides a desiredrelationship. For example, when the desired relationship is that signal1 has a greater magnitude than signal 2, a favorable comparison may beachieved when the magnitude of signal 1 is greater than that of signal 2or when the magnitude of signal 2 is less than that of signal 1. As maybe used herein, the term “compares unfavorably”, indicates that acomparison between two or more items, signals, etc., fails to providethe desired relationship.

As may also be used herein, the terms “processing module”, “processingcircuit”, “processor”, and/or “processing unit” may be a singleprocessing device or a plurality of processing devices. Such aprocessing device may be a microprocessor, micro-controller, digitalsignal processor, microcomputer, central processing unit, fieldprogrammable gate array, programmable logic device, state machine, logiccircuitry, analog circuitry, digital circuitry, and/or any device thatmanipulates signals (analog and/or digital) based on hard coding of thecircuitry and/or operational instructions. The processing module,module, processing circuit, and/or processing unit may be, or furtherinclude, memory and/or an integrated memory element, which may be asingle memory device, a plurality of memory devices, and/or embeddedcircuitry of another processing module, module, processing circuit,and/or processing unit. Such a memory device may be a read-only memory,random access memory, volatile memory, non-volatile memory, staticmemory, dynamic memory, flash memory, cache memory, and/or any devicethat stores digital information. Note that if the processing module,module, processing circuit, and/or processing unit includes more thanone processing device, the processing devices may be centrally located(e.g., directly coupled together via a wired and/or wireless busstructure) or may be distributedly located (e.g., cloud computing viaindirect coupling via a local area network and/or a wide area network).Further note that if the processing module, module, processing circuit,and/or processing unit implements one or more of its functions via astate machine, analog circuitry, digital circuitry, and/or logiccircuitry, the memory and/or memory element storing the correspondingoperational instructions may be embedded within, or external to, thecircuitry comprising the state machine, analog circuitry, digitalcircuitry, and/or logic circuitry. Still further note that, the memoryelement may store, and the processing module, module, processingcircuit, and/or processing unit executes, hard coded and/or operationalinstructions corresponding to at least some of the steps and/orfunctions illustrated in one or more of the Figures. Such a memorydevice or memory element can be included in an article of manufacture.

One or more embodiments have been described above with the aid of methodsteps illustrating the performance of specified functions andrelationships thereof. The boundaries and sequence of these functionalbuilding blocks and method steps have been arbitrarily defined hereinfor convenience of description. Alternate boundaries and sequences canbe defined so long as the specified functions and relationships areappropriately performed. Any such alternate boundaries or sequences arethus within the scope and spirit of the claims. Further, the boundariesof these functional building blocks have been arbitrarily defined forconvenience of description. Alternate boundaries could be defined aslong as the certain significant functions are appropriately performed.Similarly, flow diagram blocks may also have been arbitrarily definedherein to illustrate certain significant functionality.

To the extent used, the flow diagram block boundaries and sequence couldhave been defined otherwise and still perform the certain significantfunctionality. Such alternate definitions of both functional buildingblocks and flow diagram blocks and sequences are thus within the scopeand spirit of the claims. One of average skill in the art will alsorecognize that the functional building blocks, and other illustrativeblocks, modules and components herein, can be implemented as illustratedor by discrete components, application specific integrated circuits,processors executing appropriate software and the like or anycombination thereof.

In addition, a flow diagram may include a “start” and/or “continue”indication. The “start” and “continue” indications reflect that thesteps presented can optionally be incorporated in or otherwise used inconjunction with other routines. In this context, “start” indicates thebeginning of the first step presented and may be preceded by otheractivities not specifically shown. Further, the “continue” indicationreflects that the steps presented may be performed multiple times and/ormay be succeeded by other activities not specifically shown. Further,while a flow diagram indicates a particular ordering of steps, otherorderings are likewise possible provided that the principles ofcausality are maintained.

The one or more embodiments are used herein to illustrate one or moreaspects, one or more features, one or more concepts, and/or one or moreexamples. A physical embodiment of an apparatus, an article ofmanufacture, a machine, and/or of a process may include one or more ofthe aspects, features, concepts, examples, etc. described with referenceto one or more of the embodiments discussed herein. Further, from figureto figure, the embodiments may incorporate the same or similarly namedfunctions, steps, modules, etc. that may use the same or differentreference numbers and, as such, the functions, steps, modules, etc. maybe the same or similar functions, steps, modules, etc. or differentones.

Unless specifically stated to the contra, signals to, from, and/orbetween elements in a figure of any of the figures presented herein maybe analog or digital, continuous time or discrete time, and single-endedor differential. For instance, if a signal path is shown as asingle-ended path, it also represents a differential signal path.Similarly, if a signal path is shown as a differential path, it alsorepresents a single-ended signal path. While one or more particulararchitectures are described herein, other architectures can likewise beimplemented that use one or more data buses not expressly shown, directconnectivity between elements, and/or indirect coupling between otherelements as recognized by one of average skill in the art.

The term “module” is used in the description of one or more of theembodiments. A module implements one or more functions via a device suchas a processor or other processing device or other hardware that mayinclude or operate in association with a memory that stores operationalinstructions. A module may operate independently and/or in conjunctionwith software and/or firmware. As also used herein, a module may containone or more sub-modules, each of which may be one or more modules.

As may further be used herein, a computer readable memory includes oneor more memory elements. A memory element may be a separate memorydevice, multiple memory devices, or a set of memory locations within amemory device. Such a memory device may be a read-only memory, randomaccess memory, volatile memory, non-volatile memory, static memory,dynamic memory, flash memory, cache memory, and/or any device thatstores digital information. The memory device may be in a form a solidstate memory, a hard drive memory, cloud memory, thumb drive, servermemory, computing device memory, and/or other physical medium forstoring digital information.

While particular combinations of various functions and features of theone or more embodiments have been expressly described herein, othercombinations of these features and functions are likewise possible. Thepresent disclosure is not limited by the particular examples disclosedherein and expressly incorporates these other combinations.

What is claimed is:
 1. A method comprises: partitioning, by a computingdevice of a dispersed storage network (DSN), a data object into a firstpartition and a second partition; dispersed storage error encoding, bythe computing device, the first partition into a first plurality of setsof encoded data slices and the second partition into a second pluralityof sets of encoded data slices; generating, by the computing device, afirst segment allocation table (SAT) regarding storage of the firstplurality of sets of encoded data slices in a first set of storage unitsof the DSN and a second SAT regarding storage of the second plurality ofsets of encoded data slices in a second set of storage units of the DSN;dispersed storage error encoding, by the computing device, the first SATto produce a first set of SAT slices and the second SAT to produce asecond set of SAT slices; sending, by the computing device, the firstplurality of sets of encoded data slices and the first set of SAT slicesto the first set of storage units; sending, by the computing device, thesecond plurality of sets of encoded data slices and the second set ofSAT slices to the second set of storage units; and generating, by thecomputing device, a third SAT regarding storage of the first and secondsets of SAT slices in the first and second set of storage units.
 2. Themethod of claim 1 further comprises: determining, by the computingdevice, to partition the data object based on one of: a data objectattribute; a partitioning scheme lookup; and receiving the partitioningscheme.
 3. The method of claim 1, wherein the first SAT comprises: astart segment vault source name entry indicating a vault source nameassociated with storage of a first set of encoded data slices of thefirst plurality of sets of encoded data slices, wherein a first datasegment of one or more data segments of the first partition is dispersederror encoded into the first set of encoded data slices; a segment sizeentry indicating a number of bytes of each data segment of the one ormore data segments of the first partition; and a total length entryindicating a number of bytes of all of the data segments of the one ormore data segments of the first partition.
 4. The method of claim 1,wherein the second SAT comprises: a start segment vault source nameentry indicating a vault source name associated with storage of a firstset of encoded data slices of the second plurality of sets of encodeddata slices, wherein a first data segment of one or more data segmentsof the second partition is dispersed error encoded into the first set ofencoded data slices; a segment size entry indicating a number of bytesof each data segment of the one or more data segments of the secondpartition; and a total length entry indicating a number of bytes of allof the data segments of the one or more data segments of the secondpartition.
 5. The method of claim 1, wherein the third SAT comprises: afirst data entry region including: a start segment vault source nameentry indicating a vault source name associated with storage of a firstset of encoded data slices of the second plurality of sets of encodeddata slices, wherein a first data segment of one or more data segmentsof the second partition is dispersed error encoded into the first set ofencoded data slices; a segment size entry indicating a number of bytesof each data segment of the one or more data segments of the secondpartition; and a total length entry indicating a number of bytes of allof the data segments of the one or more data segments of the secondpartition; and a second data entry region including: a start segmentvault source name entry indicating a vault source name associated withstorage of a first set of encoded data slices of the second plurality ofsets of encoded data slices, wherein a first data segment of one or moredata segments of the second partition is dispersed error encoded intothe first set of encoded data slices; a segment size entry indicating anumber of bytes of each data segment of the one or more data segments ofthe second partition; and a total length entry indicating a number ofbytes of all of the data segments of the one or more data segments ofthe second partition.
 6. The method of claim 1 further comprises:dispersed storage error encoding, by the computing device, the third SATto produce a third set of SAT slices; and sending, by the computingdevice, the third set of SAT slices to the first set of storage units orthe second set of storage units.
 7. The method of claim 1 furthercomprises: updating, by the computing device, a directory with a firstSAT vault source name, a second SAT vault source name, and a third SATvault source name.
 8. The method of claim 1 further comprises: furtherpartitioning, by the computing device, the data object into a thirdpartition; dispersed storage error encoding, by the computing device,the third partition into a third plurality of sets of encoded dataslices; generating, by the computing device, a fourth SAT regardingstorage of the third plurality of sets of encoded data slices in a thirdset of storage units of the DSN; dispersed storage error encoding, bythe computing device, the fourth SAT to produce a fourth set of SATslices; sending, by the computing device, the third plurality of sets ofencoded data slices and the fourth set of SAT slices to the third set ofstorage units; and generating, by the computing device, a fifth SATregarding storage of the first, second, and third sets of SAT slices inthe first, second, and third set of storage units.
 9. The method ofclaim 1 further comprises: dispersed storage error encoding the firstpartition into the first plurality of sets of encoded data slices andthe dispersed storage error encoding of the second partition into thesecond plurality of sets of encoded data slices substantiallyconcurrently.
 10. A computing device of a dispersed storage network(DSN), the computing device comprises: an interface; memory; and aprocessing module operably coupled to the memory and the interface,wherein the processing module is operable to: partition a data objectinto a first partition and a second partition; dispersed storage errorencode the first partition into a first plurality of sets of encodeddata slices and the second partition into a second plurality of sets ofencoded data slices; generate a first segment allocation table (SAT)regarding storage of the first plurality of sets of encoded data slicesin a first set of storage units of the DSN and a second SAT regardingstorage of the second plurality of sets of encoded data slices in asecond set of storage units of the DSN; dispersed storage error encodethe first SAT to produce a first set of SAT slices and the second SAT toproduce a second set of SAT slices; send the first plurality of sets ofencoded data slices and the first set of SAT slices to the first set ofstorage units; send the second plurality of sets of encoded data slicesand the second set of SAT slices to the second set of storage units; andgenerate a third SAT regarding storage of the first and second sets ofSAT slices in the first and second set of storage units.
 11. Thecomputing device of claim 10, wherein the processing module is operableto: determine to partition the data object based on one of: a dataobject attribute; a partitioning scheme lookup; and receiving thepartitioning scheme.
 12. The computing device of claim 10, wherein thefirst SAT comprises: a start segment vault source name entry indicatinga vault source name associated with storage of a first set of encodeddata slices of the first plurality of sets of encoded data slices,wherein a first data segment of one or more data segments of the firstpartition is dispersed error encoded into the first set of encoded dataslices; a segment size entry indicating a number of bytes of each datasegment of the one or more data segments of the first partition; and atotal length entry indicating a number of bytes of all of the datasegments of the one or more data segments of the first partition. 13.The computing device of claim 10, wherein the second SAT comprises: astart segment vault source name entry indicating a vault source nameassociated with storage of a first set of encoded data slices of thesecond plurality of sets of encoded data slices, wherein a first datasegment of one or more data segments of the second partition isdispersed error encoded into the first set of encoded data slices; asegment size entry indicating a number of bytes of each data segment ofthe one or more data segments of the second partition; and a totallength entry indicating a number of bytes of all of the data segments ofthe one or more data segments of the second partition.
 14. The computingdevice of claim 10, wherein the third SAT comprises: a first data entryregion including: a start segment vault source name entry indicating avault source name associated with storage of a first set of encoded dataslices of the second plurality of sets of encoded data slices, wherein afirst data segment of one or more data segments of the second partitionis dispersed error encoded into the first set of encoded data slices; asegment size entry indicating a number of bytes of each data segment ofthe one or more data segments of the second partition; and a totallength entry indicating a number of bytes of all of the data segments ofthe one or more data segments of the second partition; and a second dataentry region including: a start segment vault source name entryindicating a vault source name associated with storage of a first set ofencoded data slices of the second plurality of sets of encoded dataslices, wherein a first data segment of one or more data segments of thesecond partition is dispersed error encoded into the first set ofencoded data slices; a segment size entry indicating a number of bytesof each data segment of the one or more data segments of the secondpartition; and a total length entry indicating a number of bytes of allof the data segments of the one or more data segments of the secondpartition.
 15. The computing device of claim 10, wherein the processingmodule is operable to: dispersed storage error encode the third SAT toproduce a third set of SAT slices; and send the third set of SAT slicesto the first set of storage units or the second set of storage units.16. The computing device of claim 10, wherein the processing module isoperable to: update a directory with a first SAT vault source name, asecond SAT vault source name, and a third SAT vault source name.
 17. Thecomputing device of claim 10, wherein the processing module is operableto: further partition the data object into a third partition; dispersedstorage error encode the third partition into a third plurality of setsof encoded data slices; generate a fourth SAT regarding storage of thethird plurality of sets of encoded data slices in a third set of storageunits of the DSN; dispersed storage error encode the fourth SAT toproduce a fourth set of SAT slices; send the third plurality of sets ofencoded data slices and the fourth set of SAT slices to the third set ofstorage units; and generate a fifth SAT regarding storage of the first,second, and third sets of SAT slices in the first, second, and third setof storage units.
 18. The computing device of claim 10, wherein theprocessing module is operable to: dispersed storage error encode thefirst partition into the first plurality of sets of encoded data slicesand the second partition into the second plurality of sets of encodeddata slices substantially concurrently.